Touch-responsive keyboard



Nov. 17, 1953 E. J. QUINBY ET AL TOUCH-RESPONSIVE KEYBOARD Filed Jain. 27, 1951 2. Sheets-Sheet 1 lNl/ENTORS' [OW/IV QU/NBV WALTER S. OL/WA y I ATTORNEY Patented Nov. 17, 1953 UNITED STATES FATENT OFFICE 2,659,533 ToUon-ItEsroNsIvE nEYBoARD Edwin J. Quinby, New York, N; Y., and Walter S.

OliwaL, Orange, N. J., assignors to Monroe Calculating Machine Company, Orange, N. J.,' a corporation of Delaware Application January 27, 1951, serial N6. 208.216

8 Claims. (01. 235-145) This invention relates'to touch responsive keyboards such as are applicable to" desk machines ofthe'type including calculating machines; type writers, elevator controls, and other key-operated equipment, either directly or remotely controlled.

It is an object of our invention to provide a touch responsive keyboard for calculating machines. typewriters; and the like, wherein there is noneed to do more than touch the different motionless key-representing areas on a flat surface in order to control and operate the'm'achine.

Another object is to provide control mechanism for a desk machinewhich is operable in accord ance" with the selectivetouching of motionless key-representingzones ona flat surface.

Still another object is to provide electronic equipment responsive to signals derived from a touch-controlled keyboard having stationary keysimulating spots arrayed on a flat surface.

Still another object is to provide translucent keysimulatin areas on a substantially flat: key board and means for varying the intensity of back lighting of such areas; With the accom plishment' of this obiect weare enabled togive greater brilliance many area which. has been touched and thus" to indicate a set-up of se' lecting keys'before touching an operate key.

Another object is to provide means for" varying the color characteristics of the-backlighting as applied to motionless keys on a keyboard, or key-' simulating panel.

The foregoing and other objects and advantages of our invention will be brought out inmore" detail in the description to follow. This description is accompaniedby drawings in which;

Fig. 1 shows in perspective a conventional-keyboard of the type with which this'invention'is concerned;

Fi'g. 2 shows a cross sectional elevation view of onestrip of motionless keys in association with which there is provided a means for varying the color effects of back lighting of the key'areas;

Fig; 3 shows a preferred circuit-arrangement whereby responses to the touching of key areas: on the keyboard areobtained and made useful in the control of a desk machine; and 7' V.

Fig. 4 shows a modification of the circuit arrangemeiit of Fig: 3.

The basic id'ea of a touch responsivekeyboard is one wherein thehuman fingerenters' intoa circuit arrangement when touching -one'of the key-simulating areas of the keyboard." The ele'c-' tric current which is thus caused to flow through the circuit is very minute and when carried all 2 perfectly harmless. It is, however, capable of controlling an electronic element, such as a Thyratron tube, and thus to trigger the same, causing it to operate a relay for performing. any desired function. The key-representing areas of our touch responsive keyboard are eachinclus'ive of one or two embedded conductive terminals. In one form of our apparatus, each key-simulating area is provided with only a single circuit terminal. The control grid of a Thyratron tube is connected to this terminal andds normally biased by a resistive connection to a' negative potential source terminal for normally holding the grid more negative than the cathode. Then, by touching the key, the grid potential is brought to a triggering point'sothat'the tube fires. In other forms of our equipment each key-representing area is inclusive of two embedded circuit terminals sothat when it is touched the huma'n finger alone bridges these two terminals and completes the circuit. This form of apparatus has been found to be much more sensitive than the one first described. It lendsitself also to sensitivity control which we provide for compensation'purposes where the ohmic resistance of the human skin varies with different individuals and with climatic conditions.

Referring now to Fig.1, we show therein a conventional calculating machine keyboard I having digital rows of keys 2 which are labeledO to 9 inclusive. In a calculating machine particularly, it is also necessary to provide operating keys, such as an add key 3, a subtract key 4; a-multi-plication key 5, and a division key 6. A clear key 1 is provided for clearing the machine after performing any desiredcomputation. An error key 8 is used to restore any erroneous set-up on the keyboard before touching any of the operate keys.

Referring to Fig. 2, the'cross-sec tional view therein represents a portion of one digital strip of motionless keys 2'. Y mounted individual lamp bulbs 9. each of the lamp bulbs is a cylindrical member- ID' of translucent material; preferably for use as a color filter. Each of these cylinders is mounted for rotation on a shaft ll. Different groups of such members having a'common shaft H are provided for the different digital orders of the'keys in the computing machine so the shaft H is aligned and parallel with the digital key strips.

We also provide a knurled adjusting disk I2, one perimeter portion of which is exposed above the-plane of the keyboard so that the color filterin g cylinders may be rotated as a digital order group to bring any desired one of several possible Underlying them are" Surrounding color selections between the lamps 9 and the translucent keys 2. The variation in color may be within any desired range in the visible spectrum. The advantage of having a common control for the color effects with respect to each digital order of the keys is that if it is desired to separate two adjacent columns of keys by an indication of the decimal point location, these two columns can be distinguishably colored.

We have found it to be of advantage to provide normally dim lighting of all the keys of the keyboard until any of them are touched; then, as part of the touch-responsive action, the light intensity is automatically increased under the keys that have been touched. means for adjustable control of the light intensity levels both under stand-by conditions and after the keys have been touched. Thus rheostats are included in the lighting circuits for our touch-responsive keyboard so that the two levels of brilliance may be controlled independently to meet varying conditions of incident lighting and to satisfy the demands of the individual operator. For this purpose, a control knob I3 on the side of the machine is used to adjust the initial brightness for stand-by lighting conditions, and another control knob I4 is used to adjust the full brilliance of those keys that are touched.

The sensitivity adjustment which was mentioned above preferably utilizes a control knob I5. The circuit arrangements which are controlled by these knobs I3, 14 and I5 will be set forth in the ensuing description of Fig. 3.

In the circuit diagram of Fig. 3 we show some of the key positions 2 of a single digital order in a conventional computing machine. We also indicate several operating keys 3 to 3 inclusive as in Fig. 1. Each of these keys is constituted as one or two exposed conductor terminals embedded in a key-representing portion of an insulated plate or table I. The latter is preferably composed of translucent plastic.

In the embodiment of Fig. 3, each of the keys 2 to 8 inclusive comprises an annular metal terminal I6 and another metal terminal II. The size and shape of terminal I! is not critical. In a preferred form, the character designations may be of metal supported by the insulating material within the circular area of each key. Each metallic character must itself be a circuit terminal IT in that case and be exposed to be touched at the same time as the ring I6. The terminal I6 is connected to the first grid of a gaseous discharge tube It) while terminal I7 is connected to a bus line leading through resistor I9 and thence to a manually controlled switch 23 having two positions. In one of these positions, connection may be made from ground through the resistor I9 to all of the key terminals II. In the other position of the switch 2!] it is arranged to supply a positive voltage of, say, 24 volts D. C., to each of the terminals I1. The voltage of this source is not critical, but may, if desired, be as high as 100 volts.

Each of the gaseous discharge tubes I8, and 33 is preferably of the tetrode type. That is to say, it has an anode, a cathode and two grids, the first grid being a control grid and the second grid being a shield grid in connection with the cathode.

Each of the anodes in the tubes I8 is individually connected through the winding of a relay 2| and thence to a bus line 22 leading through contacts 23 of a circuit opening relay 24. This We also provide relay is designed for fast-operate-and-slow re* lease action. A D. 0. potential of, say, 140 volts is supplied through bus 22 to each of the windings of relays 21 and thence to the anodes of the respective gaseous tubes I8, except when relay 24 is operated to open its contacts 23. The cathodes of tubes I8, 25 and 33 are grounded, as is the negative terminal of the 140 volt source.

The bus 22 is extended to the windings of re lays 23 and 34 as well as relays 2I. The keys 2 control gaseous tubes 25 individually. When any of these tubes is triggered the relay 23 or 34 which is in series therewith operates.

There is a relay and gaseous tube circuit corresponding to each of the selecting keys 2 and also corresponding to each of the operate keys 3-8 inclusive. Relays 2I have different control functions to be performed in the operation of a machine. That is to say, they cause a calculat ing machine, for example, to be electrically controlled the same as though its conventional keyboard were to be manipulated. Accordingly, each of these relays has circuit closing contacts 26 for applying ground potential to some one or another of the various control circuits by which a computing machine may be electromagnetically operated.

Since the keys 2 have a selecting function to be performed prior to the operate function of the keys 3-! inclusive, it will be understood that circuit closures made by contacts 21 of the operated relays 23 will be used to carry out any of the normal selecting functions of a calculating machine keyboard. Thus, the grounded relay contacts 2'! when closed against their respective front contacts will serve to carry out these keyselecting functions, and to operate any electromagnetic devices that may be provided in the calculator.

Operatively associated with each of the relays 23 is one of the indicating lamps 9 that were referred to in the description of Fig. 2. In order to vary the intensity of the lighting in these lamps beneath the key spot areas, transfer contacts 28 on relays 23 are used. Each of these transfer contacts, when resting against its associated back contact, causes a potential to be fed to the connected lamp 9 from an intermediate tap 29 on the secondary winding of a transformer 30. The primary winding of this transformer is supplied from any suitable alternating current source, say volts and 60 cycles. This tap 29 is connected to the said back contacts of relays 23 through a rheostat 3I which is adjustable by means of the control knob I3, as shown in Fig. l. The front contacts associated with the movable contacts 28 on relays 23 are all connected through another rheostat 32 to an outer terminal on the secondary winding of transformer 30. Thus, the full voltage across this secondary winding may be supplied through the rheostat 32 to the lamps 9 whenever an associated relay 23 is operated. The return circuit common to all of the lamps 9 is connected to the other outer terminal on the secondary of transformer 30.

Operatively associated with the error key terminals 8 is a gaseous tube 33, the connections for which are similar to those of the other tubes. The anode of tube 33 has a connection through the winding of a relay 34 to the bus line 22 and thence through the circuit-breaking contacts 23 on relay 24 to the positive D. C. source v.). Since the error key has no function to perform 7 range of utilization devices and different types thereof.

7 We claim:

1. A keyset comprising a translucent table of insulating material, conductor terminals exposed on the front side of said table and placed according to keys of a conventional keyset, gaseous discharge tubes each fired by a finger touch on a respective one of said terminals, relays operated, each on firing of said tube lamps each arranged and adapted to illuminate a difierent small area surrounding one of said conductor terminals, a stand-by voltage source for lighting said lamps dimly, an indicating voltage source for lighting selected ones of said lamps with additional brilliance in response to the operation of corresponding ones of said relays, and adjustable rheostats in the circuits of said lamps whereby the intensities of illumination are regulable both under stand-by and indicating conditions.

2. In a keyboard of the class described, an insulating table having exposed contacts mounted thereon in a key-simulating array, a plurality of gaseous discharge tubes for selective control of utilization devices, each tube having electrodes for space path conduction and a control electrode to produce such conduction, an electrical connection between each said control electrode and a corresponding contact in said array, operating and biasing potential sources suitably connected to the electrodes of each of said tubes for maintenance of the same in one of two stable states, a relay connected to each tube and energized when the latter is in a conducting state and control circuits for selective application of ground potential to desired ones of said control electrodes, each of said control circuits being closeable through the flesh of an operator when touching one of said contacts.

3. In a touch responsive keyboard, the combination of a plurality of conductor terminals arranged as keys, a gaseous discharge tube for each terminal having an anode and a grid means for normally maintaining the grids of said tubes at a potential adapted to cut off the tube, each said grid being connected to a said terminal to effect firing of its tube on contact of a finger with the terminal, a relay connected to the anode of each tube and operated on firing of the latter, means to illuminate each said terminal dimly, means controlled by each relay to increase the brilliance of the illumination of the associated terminal on operation thereof, and utilization means controlled by the operation of said relays.

4. In a touch responsive keyboard, the combination of a plurality of conductor terminal pairs arranged as keys, each pair being adapted for bridging by a finger, a plurality of gaseous dis charge tubes normally biased beyond cutoff, but each fired on bridging of the associated terminals, means for so biasing said tubes, said means being by-passed by the bridged terminals a relay in circuit with each tube and operated on firing of the latter, means for normally illuminating each terminal pair dimly, means controlled by each relay for increasing the brilliance of the illumination on its terminals, and utilization means controlled by each relay.

5. In a touch responsive keyboard, the com- 8. bination of a plurality of conductor terminal pairs arranged as keys, each pair being adapted for bridging by a finger, a plurality of gaseous discharge tubes normally biased beyond cutoff. but each fired on bridging of the associated terminals, means for so biasing said tubes, said means being by-passed by the bridged terminals means for adjusting the bias on the tubes to compensate for difierences in conductivity of human fingers, a relay in circuit with each tube and operated on firing of the latter, means for normally illuminating each terminal pair dimly, means controlled by each relay for increasing the brilliance of the illumination on its terminals, and utilization means controlled by each relay.

6. The combination according to claim 3 and including rheostat means for adjusting the bias on the tubes to compensate for difierences in concluctivity of the human body.

7. The combination according to claim 6 wherein the means for illuminating the terminals dimly and the means for increasing the brilliance of the illumination include a lamp for each terminal, a first circuit common to all of the lamps and effective to illuminate each lamp dimly when the associated relay is de-energized, a sec-- ond circuit common to all of the lamps and effective to illuminate each lamp more brightly when the associated relay is energized and an adjustable rheostat in each said circuit to control the brilliance of the lamps under both conditions.

8. The combination according to claim 5 Wherein the means for illuminating the terminals dimly and the means for increasing the brilliance of the illumination include a lamp for each terminal, a first circuit common to all of the lamps and effective to illuminate each lamp dimly when the associated relay is de-energized, a second circuit common to all of the lamps and eiiective to illuminate each lamp more brightly when the associated relay is energized and an adjustable rheostat in each said circuit to control the brilliance of the lamps under both conditions,

EDWIN J. QUINBY. WALTER S. OLIWA.

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